Quantum Xchange uses quantum technology to guard encryption keys.

In the past, the technology the company sells, called quantum key distribution (QKD), could only be used in a fiber optic cable between two endpoints over a short distance—at most 60 miles.

But Quantum Xchange says the new method it has developed can protect data being transmitted to multiple endpoints, over any distance and across standard telecom networks.

The demand for more secure methods of transmitting encryption keys has been sparked by events, such as the Edward Snowden leaks and, more recently, U.S. concerns about Chinese interest in tampering with telecommunications hardware, that have raised public awareness of nation states' abilities to tap fiber optic networks and suck in vast amounts of data.

Quantum Xchange, a startup based in Bethesda, MD., operates a dedicated QKD transmission line between lower Manhattan and data centers in New Jersey where many big banks and Wall Street firms conduct back office operations and trading.

Prisco says many Wall Street banks and hedge funds are already using this cable to transmit encryption keys and other vital data, such as trading algorithms, but he says he does not have permission to name these customers publicly.

The company also has plans to create a much longer QKD network carrying signals between New York and Washington, D.C., by using what are called "trusted nodes," positioned every 60 miles or so, to boost the signal.

He also says that Quantum Xchange has been working with major telecommunication equipment manufacturers, such as Ciena, Gemalto and Thales to ensure their standard encryption hardware will accept a quantum key.